Annealing furnace



Aug. 3, 1943. c. B. HOAK ANNEALING FURNACE Filed Jan. 23, 1940 ,5 f c6 @Wo 3 Sheets-Sheet l Aug. 3, 1943. c. B. HoAKv ANNEALING FURNACE 5 sheets-Sheet 2 Filed Jan. 23, 1940 3; 53 24AM/rcel?. /fonk @Mm/ws Aug. 3, 1943. c. B. HoAK ANNEALING FURNACE Filed Jan. 2s, 1940 3 Sheets-Sheet 3 0 W m M M a a Mm Patented 3, 1943 FURNACE Clarence B. Hoak, Steubenville, Ohio Application January 23, 1.940, SerialNo. 315,234

(ci. 26a-5) v 2 Claims.

My invention relates to new and useful improvements in an annealing furnace particularly adapted for the annealing of rolled steel strip and has for its principal object the provision of a furnace of the mutiie type including an outer heat insulating wall or cover and an inner heat conducting muiiie, the mule having a chamber for enclosing the material to be operated upon. Another object of the invention resides in the provision of a novel form of muliie or mullies including a regulating damper or dampers whereby the flow of heat or cooling currents may be regulated at the will of the operator and to meet the requirements of the material being operated upon, it being understood it will be desirable to change-the heating currents according to the weight of the material, it being necessary to circulate more heat around a larger mass or unit than it is around a smaller mass or unit,` in

order to bring all of the units of steelup through their heat range at the same rate. By the use of the regulating damper or dampers the heating .gases or cooling air currents can be regulated to vary the rate of heating or cooling of the interior of the coils. of steel, wire, etc.

With the above and other objects in View, my invention consists lin the novel details of construction, and arrangement of parts, described in the following specication and illustrated in the accompanying drawings, and while I have illustrated and described the preferred embodi` ments ofthe invention, as`they now appear to me, it will be understood that such changes may be made as will fall within the scope yof the appended claims.

In the drawings:

` Fig. 41 is a transverse vertical section through a furnace of the character described with yparts shown in elevation.

Fig. 2 is a horizontal section through the muille cover of Fig. 1, the muile base or pan being shown in top plan.

Fig. 3 is a detail showing in elevation one of the dampers or regulators used in connection with passages through the muliie base or pan.

Fig. 4 is a view similar to Fig. 1 showing .a slightly modified form of furnace.

Fig. 5 is a transverse vertical section through a slightly modified form of muiile.

Fig.` 6 is a top plan of the muiile shown in Fig. 5. l

Fig.` '7 is a transverse vertical section through a. further modifiedV form of muilie withv parts shown in elevation.

A Fig. 8 is a top plan of the muilieshown in Fig. 7

with the dampers. or regulators swung into substantially open position; and

Fig. '9 is a fragmental transverse vertical sectionl through Aa still further modified form of muiile with parts shown in elevation.

Referring more particularly to Figs. 1 to 3 .inner partition wall 2,' cylindrical in form, and

providing the passage 3 for the heating or cooling currents. The-outer wall or cover B is further4 provided with the circumferentially space/d openings #and at 5 I have lshown burners having portions projecting throughthe openings 4 and terminating-fin the passage 3. Peep holes are shown at 4 and are adapted, when not in use, to be closed by the plugs 5'.

The inule cover C includes the outer cylindrical wall 6, inner cylindrical wall 1 and top 8, the top 8 being formed'with an opening 9 registering with the central passage or opening formed through the munie cover by theinner wall l. The opening 9 is adapted to be closed by the damper or regulator I0 pivotally connected to the topV 8 at H, this being shown more particularly in Fig. l of the drawings. The muflie cover C also includes the cylindrical hood I2 which is open at its bottom and closed at the top, this hood being connected to the walls 6 and I by the circumferentially spaced vertical strips 6', shown more particularly in Fig. 2, to be movable therewith. The hood is of such a size as to be spaced from the outer wall 6 and` the inner wall 1 and there is also a space above the hood all of which is quite clearly illustrated in Fig. 1. The outer Wall 6 is provided, adjacent its lower end, with circumferentially spaced openings I3 and the inner wall 'I is provided, adjacent its upper end, with the circumferentially spaced openings I4 and adjacent its lower end with the circumferentially spaced openings I5.

The muille base or pan D is formed with the horizontal circumferentially spaced openings'or passagesA I6 which extend from the outer surface of the base or pan and communicate with a vertically extending opening I1 formed through the base or pan and which opening communicates with the exhaust. opening I. 4Pivotally connected at I8'to the outer surface or edge of the base or pan D are the dampers or regulators I9 in the form of plates, these plates or dampers being swung to open or close the openings or passages The hood l2 forms the cylindrical chamber 23 4the furnace and muflle same'in a manner which will be later apparent. Y

which receives the material 24, to be operated upon. the material resting upon the mule pan or base and enclosed by the muille cover C.

In the formof the invention shown in Figs. 1 to 3 inclusive of the drawings the gas currents will pass in the directions shown by the arrows l and the flow of the heating currents through the muiile cover and muflle base or pan maybe regulated by the dampers or regulators Il) and I9. I am, of course, aware that in the annealing of material it is old to use a mufile including a mufe cover and base and that the heat yis circulated around the munie and through passages therein.

However, I am not aware of the previous use of dampers or regulators for controlling the passage of heat through both the muflle hood and muilie base or pan, this being advantageous in the annealing where different size masses of material are used. Where a larger mass is to be treated more heat is necessary than is required in the treatment of smaller masses. vIf the temperature of the base or pan is to be increased the regulators or dampers I9 will be swung to open these passages and if it is desired to increase the heat through the-munie vcover C the damper or regurequire a greater amount of heat than the other unit. When it is desired to cool the cooling currents may be passed through the furnace in the same directions as is the heating current and these cooling currents may be regulated or controlled by the dampers or regulators I0 and I9.

It will be further understood that the furnace wall or cover B, as well as the :nume cover C, may

be raised in any of the usual well-known ways forA placing the material to be operated upon onthe muille base or pan or for the removal thereof. The dampers I0 and I9 may be adjusted at will by hand or by the engagement of a suitable instrument. `In Fig. l of the drawings I have shown al rod I0', having a hook II', at one end and engaged in an opening in the damper Il), the rod passing through one of the peep holes 4' and formed -at -its outer end with a hand-engaging portion I2'. By manipulation of the rod the damper may be swung on its pivot.

In Fig. 4 of the drawings I have illustrated a slightly modied form 'of furnaceI and mule in which E shows the furnace base or floor, F the outer wall or cover adapted to, be supported by the base or door E, G the muiile cover, and H- the mule base on which the cover G is supported.

-An exhaust opening is formed in the base or fioor E and extending through this .opening 25, and rotatably supported in a manner not shown,

is a shaft-26 on the upper end of which is secured a fan 21'5bperable in a recess 28 formed in the muille base-H. This fanacts as a suction fan for drawing the heating or cooling currents through andfor discharging 'the The outer wall or cover Fis formed, adjacent its lower end, with the circumferentially spaced exhaust openings; 29"a.nd in substantial alignment with these openings are grooves or passages 3|) 3 formed in the bottom surface of the mul'e base H. These. grooves or passages extend from the sage above outer edge of the base to the recess 28 and also communicating with this recess 28 is an opening 3| which extends to the upper surface of the base. Extending from the opening 3| are the circumferentially spaced openings or passages 32 which are adapted to be closed at their outer ends by means of the dampers or regulating plates 33 pivotally connected to the marginal edge of the base l-I as shown at 34. At 35 I have illustrated burners which pass throughthe top cf the cover F downwardly to the position shown in .the drawings. While these burners are, of course, adapted for supplying heat interiorly of the furnace they may, when desired, be used for conveying cool air in the cooling operation.

The muflle cover G includes the concentrically arranged inner and outer walls 36 and 31 respectively, between which is supported, by the circumferentially spaced Vertical strips 36', the cylindrical hood or cover 38, this hood 38 forming a chamber 39 for the reception `of the material 40 which is preferably in the form of rolled sheet strip. The hood is of such a size as to'leave passages between. the same and the inner and outer walls 36 and 31 as well as a space or pasthe top thereof.. The muilie cover is also formed with the upper and lower top plates 4| and 42 respectively, forming a space 43 therebetween, and each of these top plates 4| and 42 is formed with a central opening communicating with the central passage 44, formed by the inner wall 36, and the lower end of this passage 44 communicates with the opening 3| in the base H. The

outer wall 31 is formed with the circumferentially spacedopenings 45, adjacent its lower edge, and the inner wall 36 is likewise formed with circumferentially extending openings 46. The top plate 4.2 of the mufe is formed with the circumferentially spaced openings 41 and inv operation the heating or cooling currents will be passed in a direction indicated by the arrows, passing through the openings 45, then around and over the hood 38 Ato be discharged through the openings 46 into .the

passage 44, from which they are drawn'by the fan 21 through the opening 3| and discharged outwardly through the grooves or passages 30 and finally through the vopenings 29 in the wall or cover F. Y

Fivotally connected at 48, to the top plate 4|,

, is a damper or regulating plate 49, and this plate is adapted to bepositioned as shown in Fig. 4 to close the opening in the top plate 4|. When desired this damper or regulator plate 49 may be swung to uncover the central opening in the plate 4I so that the heating currents or cooling currents may be directed through thetop plate opening and supply an additional amount of heating or cooling currents through the opening or passage 44. It will be understood that the top plates 4I and 42 form a space therebetween which is not closed at'the marginal edge so that a certain amount ofthe currents may pass therebetween and throughthe openings 41,

The heating or cooling currents, passing through the base H, may be regulated by the damper plates 33. When it is desired to pass currents through the openings 32 the damper plates may be swung to uncover the outer ends of the openings or passages 32 and either heated or cooled air may be drawn through these passages or openings thereby regulating the temperature of the base. The dampers or regulating plates 33 and 49 may be adjusted by hand or suitable instrument.

1t wm be noted that in Fig. 4 of the drawings.

elusive I provide novel means for regulating the air currents so that the currents may be regulated for masses of material varying in size. At 58 I have illustrated sand or luting for forming va. seal between the muiiie cover G and muflle base H.

In Figs. and 6 of the drawingsI haveillustrated another form of munie without illustrating any particular form of outer furnacegjconstruction., In this form of the invention the -mumel l cover is lillustrated generally at a and the munie `base or pan at b. The muiile base or pan is formed with -the central vertically extending opening 5| and leading from this opening 5| are the horizontal circumferentially spaced openings 52 which lead to the marginal edge of the base or pan. For closing'the outer marginal ends of these openings 52 I provide the damper or regulating plates 53 which are pivotally connected at 54 and these plates or dampers may be operated to regulate the amount of heating or cooling currents passing through the base or pan. In its upper face or surface this base or pan b is formed with the circular concentric grooves 55 and 56 and these grooves receivel the lower ends of the walls of the munie cover, as shown, luting or sand being placed in the grooves as shown at 51 to form a seal between the muiile cover and base or pan.

The ymulile cover, in the form of theinvention disclosed in Figs. 5 and 6, includes thel inner and outer concentric circular walls 58 and 59, spaced apart to provide a chamber 60, to receive the mass of material 6| to be operated upon. At vthe top the walls 58 and 59 are connected by a top plate 62. The inner wall 58 forms a central passage in which is positioned a cylindrical member 63, closed at the top by the plate 64, but open at the bottom, with its lower end received in the groove or recess 56. The member 63 is connected to the wall 58 by the circumferentially spaced vertical strips 63. Positioned within the cylindrical member 63 are the vertically extending tubes or pipes 65, the upper ends ofthe pipes or tubes extending through the top plate 64 while the lower ends thereof are spaced above the lower end l of the member, and above the top surface of the mutlle base or pan b, as shown more particularly in Fig. 5 of the drawings. At 66 and 61 I have shown re-enforcing plates for4 properly positioning the tubes or pipes 65 within the cylindrical member 63. Pivotally connected to the top plate 64, of the cylindrical member 63 at 69, are the dampers or regulating plates 68, which are adapted to normally be swung to close the upper ends of-the tubes or pipes 65. The dampers or regulating plates 68 may be adjusted by hand or suitable instrument. 'Secured to the outer face of the wall 59, of the mule cover, are the strengthening Ts 10, which extend to the lower end of the wall and are received in the groove 55, in the base. or pan b. At 1| I have indicated hooks secured to the muille, cover so that operating mechanism may bezconnectedV thereto for raising or lowering the cover.

When the muiiieeis positioned in a' furnace the heating or cooling currents will passaround the outer wall 59, of the muilie cover over the upper surface of the cover, Aand downwardly into the opening or passage formed between the inner wall 58 and the wall of thecylindrical member 63. It `will be noted that there is no outlet at the bottom of this passage Vbut i the currents passing downwardly therein will again nd their .way upwardly. When it is desired to supply an additional amount of heat the dampers or. regulator `platesz681ay be swung open th'e upper ends of the tubes or pipes 65 and then the heating or cooling Acurrents may pass downwardly through thesepipesor tubes and be .exhausted through i the opening 5| in the base or pan b. The temperature of the base' or pan b may be regulated by operating the dampers o'r regulator plates 58. Normally the currents will be contacted with the upper surface of the base or pan and heat the same to a certain. temperature. When desired the dampers orregulator plates 53 may be swung to open the outer ends of the openings or passages 52 so that currents of heating or cooling air may pass through the openings or passages.

In Figs. '1 and 8 of the drawings I have shown a still furthermodied form of muiiie adapted for use in a furnace and this form of muflie includes the muiiie cover c and the mule base d. The base is formed centrally with the exhaust openings 1 2 and 13.

The muflle cover c includes the cylindrical concentric walls 14, 15, 16 and 11. The walls 14 and form a chamber 1-8 closed at the top by the plate 19,to`receve the material 80 to be operated upon, it being noted thatthe roll of material will rest upon the upper surface of the muflle base d. The cylindrical Wall 11 forms the passage 30, the wall 16 forms the passage 8| and the wall 15 forms the passage 82. The cylindrical members 15, 16 and 11 are connected by the transversely extending rods or pins 83, adjacent the top and bottom ends. As shown more particularly in Fig.4 7 of vthe drawings the bottom edges of the cylindrical Walls 14, 15, 16 and 11 normally rest upon the upper surface of the base d and also received on the base is a ring or band 84 which forms a space or what might be termed a pan f or receiving the sealing sand or luting shown at 85. The band or ring 84 is connected to the wall 14 of the muflle cover by the chains 86. Sand or luting may alsobe positioned on the base din the passage 82 as shown at 81.

The cylindrical wall 16 is formed with the vertically and ciroumferentially spaced openings 88 while the cylindricalwall 11 is provided with the circumferentially and vertically spaced openings 89. c

For normally closing the upper ends of the passages 80, 8| and'82 I provide the dampers or Aregulator plates 90, 9|, and 92 which are pivotally connected to the top plate 19 at 93 and may be adjusted by hand or suitable instrument, such as is shown in Fig. 1. The damper or plate 90 is provided with the central opening 94 which when the plates are in closed positions communicates with the passage 80. The damper or plate 9| is formed with the arcuate-shaped elongated openings which normally register with the passage 8|. This plate 9| is also formed centrally with a portion 96, between the arcuate-shaped openings 95 to overlie the opening 94v in the plate 90 when the plates or dampers are in closed position. The top plate or damper 9,2 is formed similar to the damper or plate 9| with th'e elongated arcuate-shaped openings 91'and central portion V98. However, the openings 91 are nearer the marginal edge of the damper or plate 92 than are the arcuate-shaped `openings 95 of the plate 9|. When Ythe plates or dampers are in the position shown in Fig. 7 of the drawings they will close theends of thepassages 80, 8| and 82, the plate 90 overlying the ends of the passages 8| and 82, the central part 96 of the damper or plate 9| overlying the central opening 94 of the plate ordamper 90 and the damper or plate 9| underlying the arcuate openings 91 in the damper or plate 92. When in this position thevupper ends of the passages 80, 8| and 82 are closed. When it is desired'to open the passage 80 the plates 9| and 92 are swung on the pivot 93 so as not to overlie the plate 90 and as the opening 94, in the' plate 90, registers with the passage 80 heating or cooling currents may pass through the opening 94 and passage 80. If it is desired to open the end of' the passage 8|, while still keeping the passages 80 and 82 closed, the

'plates 90 and 91 willbe swung and-this leaves the openings 95, in the plate 90, registered with the passage 8|. When it is desired to open the passage 82, While keeping the passages 80 and Y8| closed, then the plates 90 and 9| will be swung may be found desirable by swinging the diiierentV dampers orplates or combinations thereof.

From the above detailed description it will lbe seen that when the muiiie is positioned in the furnace the heating orv cooling currents will normally pass therearound. Additional or less heating or cooling currents may be obtained by regulating the damper plates 90, 9| and 92 to permit the heating or cooling currents to enter the passages 80,. 8| and 82. The currents may pass from the passage 82 into the the openings 88 and from the passage 8| into the passage 80 through the openings 89. The: currents will be exhausted through the openings` 12 and 13 in the mule base. At 98 I have shown hooks to beengaged for raising and lowering the mule cover.

In Fig. 9 of the drawings a further modified i form of muiile is illustrated fragmentarily. In

this form of my invention the muiile cover is shown generally at e and the muille base at j, the muille base having an exhaust passage shown at 99. The muiile cover consists of the cylindrical walls |00, and |02, the wall |02 being connected to the wall .|0| by the circumferentially spaced vertical strips |0|. The upper ends of the walls .|00 and |0| are connected by the top plate |03 to form a chamber |04 for the material |05 to be operated upon. The cylindrical wall |02 is spaced from the wall |0| to form the passage |06 into which the heating or cooling currents will be discharged and circulated as shown by the arrows. The cylindrical wall |02 forms a chamber |01 closed at the top by the plate r,i 09 kand at the bottom by the plate |09, a central opening'being formed in each of the plates'for communication with ends of a coiled pipe or tube ||0 received in the chamber |01. The lower end of the coiled pipe or tube ||0, communicating with the central opening in the plate |09, communicates with the exhaust opening 99 in the muflie base f. As stated ordinarily the heating or cooling currents from the furnace will pass'around and over the munie cover'e for entrance into the passage |06 as shown by the arrows. When it is desired to increase the heating or cooling currents the same may be discharged into and through the coiled pipe or tube H0. Normally the uppery end of this coiled pipe or r regulating plate pivotallyhconnected at H2, as shown in Fig. 9. When it is desired to pass the currents through the coiled pipe or tube the tube is closed by the damper orpassage 8| through ling or cutting off damper or regulating plate will be swung on its pivot ||2, by hand or suitable instrument, to uncover the upper end of the coiled pipe or tube so that the currents may pass therethrough. Supported on the muiiie base f is a band or ring ||3 concentric with the wall |00 and spaced therefrom. 'I'his band forms a space for the reception of the sealing sand or luting |04.

While I have illustrated several modifications of my invention it will be seen that in each instance I have shown Ymeans for regulating the heating or cooling currents so that the amount of heating or cooling air may be 'regulated according to the size of the mass of material being operated upon. In each of the `forms of the invention the muie cover is provided with dampers or regulating plates controlling passages and in some instances there are controlled passages formed in the mufle base or pan. My improved forms of muiile may be used in connection with various forms of furnaces and, as I have previously stated, while in the forms of the invention disclosed in Figs. 1 to 4 inclusive of the drawings I have only illustrated a single mufiie or unit within the furnace a plurality of the same might equally as well be used. When this is done, by the use of my regulating dampers or plates the cooling or heating currents Imay be regulated or varied so that in one mule or unit a large mass of material may be treated while in another unit or mutlle a smaller mass may be treated.

Having fully described my invention what I claim as new and desire to secure by Letters Patent is:

1. In an annealing furnace having a base and a removable insulating cover, a muiile supported on the furnace base and within the insulating cover; the mufiie including a base and a removable cover, the mule base having a vertical opening and horizontal passages leading therefrom to the margin of the base and the removable cover having a passage therethrough and a surrounding chamber to receive and enclose the material to be operated upon, me cover passagel being arranged for communication with the. interior of the furnace, to receive heating or cooling currents therefrom, and with the vertical opening in the base, a member operable relative to the end of the passage in the cover for formcommunication with the `interior of the furnace and controlling the flow vof currents from the interior of. the furnace to' and through the passage, and members mounted on the margin of the base and operable to opener close the ends of the horizontal passages at the margin of the base.

2. A muiile forl annealing furnaces including -a base and a removable cover, the base having a vertical opening and horizontal passages leading therefrom to the margin of the base and the removable cover having a passage therethrough to receive heating or cooling currents and a s urrounding chamber to receive and enclose the materia] to be operated upon, the cover passage being arranged for communication with the vertl- 'cal opening in the base, a member operable relforming or cutting off communication to the passage, and members mounted on the margin of the base and operable to open or close the ends of the horizontal passages at the margin of the base.

CLARENCE B. HOAK. 

